Replaceable tooth



' Dec. 1, 1925 W. L. MASON REPLACEABLE TOOTH Filed Sept. 29. 1924 INVE TOR zfiazierz. fi mrn BY fl wmix ATTORNEYS Patented Dec. 1, 1925.

UNITED STATES W'ALTER L. MASON, OF RED BANK, NEW JERSEY.

REPLACEABLE TOOTH.

Application filed September 29. 1924. Serial No. 740,616.

To all whom it may concern:

Be it known that I, VVALTER L. MAsoN, a citizen of the United States, and a resident of Red Bank, in the county of Monmouth and State of New Jersey, have invented a new and Improved Replaceable Tooth, of which the following is a full, clear, and exact description.

This invention relates to a replaceable tooth. An object of the invention is to provide a simple and efficient cooperation between a tooth and a backing whereby the two may be easily and firmly united without materially affecting the strength of the tooth, and for the purpose of permitting it to be mounted on a backing with a minimum liability of its working loose or being subject to undue strain when in the mouth.

The invention is illustrated in the drawings, of which Figure 1 is a perspective view of the rear of the tooth with the back plate applied;

Fig. 2 is a partial section therethrough;

Fig. 3 is a horizontal section therethrough on the line 33 of Fig. 2;

Fig. 4C is a perspective view of the tooth itself viewed from the rear; and

Fig. 5 is a perspective view of the backin plate.

The form of the invention shown in the drawings is a preferred form, although it is understood that modifications in the construction and arrangement of the parts and in the character of the materials used may be adopted without departing from the spirit of the invention as set forth in the appended claims.

Hitherto replaceable teeth have involved the use of slots and grooves of such dimensions that the engagement with the slot or groove of apin or tongue or rib, and their cooperation during the use of the teeth, has caused the teeth to be very likely to be injured or fractured due to being weakened by the formation of such large slots.

My invention in general comprises making a small hole in the lingual surface of a tooth, inserting a split pin therein, and cementing or burning it in place; disposing a back plate against the lingual surface of the tooth said back plate having an aperture therein through which the ends of the split pin can extend; then bending the ends of the split pin against the rear face of the back plate, preferably to have them lie in a recess formed on the rear surface so that they do not lie above the rear surface of the back plate; and then burning or cementing these bent ends of the pin in place in said recess. By this construction I provide a strong union between the back plate and the tooth which can be very easily made and, at the same time, the degree to which either the back plate or the tooth are cut away is negligible, so that the strength of either one of them is not materially affected. 3

The preferred form of theinventi on shown in the drawings comprises, preferably, a porcelain tooth having labial, cervical, occlusal and lingual surfaces, as shown. A slot or hole 1 is formed in the lingual surface of the tooth. In this slot a pin is disposed, this pin preferably being in the form of a strip of metal 2 bent on itself and having free ends which project from the lingual surface. This pin may be fastened in the hole or socket in any suitable manner, preferably by cementing or burning it in place. A backing plate 3 is to be disposed against the lingual surface. This plate has its lower end bent over as at 4; to lie partly under the occlusal surface of the tooth, whereby a firm additional support for the tooth is provided, so that the tooth has practically no chance to get out of alignment with respect to the plate 3. This plate is provided with an aperture 5 of substantially the same dimensions as the cross section of the pin and on its rear surface is provided with a recess 6 (see Fig. 3) into which the free ends of the pin are bent so as to be disposed therein beneath the rear surface of the plate. These bent ends of the pin can thereupon be suitably fastened into the recess, by soldering. cementing or otherwise. It will be noted from Fig. 5 that the lower end of the back plate is broad and tapers to a thin edge and, at the same time, is'bent over, as shown particularly in Fig. 2, to engage the occlusal surface of the tooth.

It will be obvious, therefore, that this cooperation between the back plate and the tooth is effected in a simple manner and results in a strong, durable union, the integrity of the tooth and the plate having been impaired only very slightly and not any more than absolutely necessary, so that the liability of fracture in the use of the tooth is substantially eliminated.

As shown more particularly in Figures 1 and 2, the backing 3 forms the finished surface for the porcelain tooth when. the same has once been secured in place, and" a cement or solder has been applied to the bent end 6 of the metal strip 2 so that when the solder or cement has been applied the outer surface of the backing will present a. smooth and continuous surface.

\Vhat I claim is c 1 A replaceable tooth having a split pin imbedded in the-body of tho'tooth and? having its free ends proj cting from, the lingual, surface thereof, a backplate disposed against the lingual surface and forming a finished section of the tooth, said back plate having an aperture therein and a recess on its rear face, the free ends of the pin projecting through the aperture and being bent against the rear face of the plate and seated in the recess, saidrecessadapted to receive a cement for fastening, the bent. ends in said recess and to provide asmooth surface on the back plate.

2. A replaceable tooth having a split pin imbedded in the body of the tooth and having its free ends projecting from the lingual' surface thereof, a back plate disposed against the lingual surface and fol-min a finished section of the tooth, said back plate having an aperture therein and a recess on its rear face, the free ends of the pin projecting through the aperture and bent against the rear face of the plate and seated in the recess, said recess adapted to receive a cement for fasteningthe hack ends in said recess and to-provide' a smooth surfaceon the back plate, the-lower end of the plate being tapered to athin edge and bent over so as to engage the occlusal surface of the tooth.

\VALTER' L. MASON. 

